A vehicle may include an undercover made of synthetic resin including thermoplastic. The undercover may be produced by forming a synthetic resin sheet into a designed form.
Irregular portions of the undercover are continuously formed to increase stiffness of the undercover. The irregular portions may be formed by altering a thickness of the sheet during the production of the undercover. In this case, protrusions and recesses may be formed on and in front and back surfaces of the undercover. Namely, flatness of the front surface (a surface to face a road surface) may decrease. This may increase wind drag resulting in decrease in aerodynamic performance and roadholding quality of the vehicle.